1. Field of the Invention
The present invention relates to touch sensing technology and more particularly, to a mutual capacitance touch sensing device and a sine wave measuring method used in the mutual capacitance touch sensing device, wherein the sine wave generator uses a clock to generate sine waves according to a lookup table being loaded therein, and the measurement unit scans sensing signals subject to the lookup table in the sine wave generator, and therefore, the invention can generate sine waves and detect sensing signals by means of the lookup table, simplifying the loop operation of the mutual capacitance touch sensing device and increasing its operational efficiency.
2. Description of the Related Art
In order to fit with human intuition, touch sensing devices are widely used in modern electronic products, enabling the user to control electronic products conveniently by means of a touch of a finger or stylus.
A touch sensing device generally comprises a touch sensing panel having arranged therein a plurality of driving lines and sensing lines to form a plurality of crossover points, a driver module electrically coupled with the driving lines, a sensor module electrically coupled with the sensing lines, and a processor electrically coupled with the sensor module. The driver module is controlled to provide a driving signal to the driving lines. At this time, the driving signal at each driving line is coupled to the respective sensing line through the respective crossover point. Thus, the sensor module scans the sensing signal at each crossover point, and transmits each measured signal to the processor for analysis. Subject to the capacitive coupling amount at each crossover point and the relative location data, a respective reference value is obtained. When a user operates the touch sensing device, the measured signal corresponding to each crossover point is compared with the respective reference value. If the difference between the measured signal and the respective reference value is zero, it means the touch sensing panel is not touched or covered by an external object. On the contrary, if there is a difference between the measured signal and the respective reference value, it means the touch sensing panel is touched or covered by an external object.
In the application of the aforesaid prior art touch sensing device, every operation, either transmitting a driving signal, measuring a sensing signal or determining a touch state, must be achieved through different component parts of the touch sensing device. Thus, this prior art design of touch sensing device complicates the loop operation, lowering the operational efficiency.